Robert Oster Viola is an unusual but interesting purple. It reminds me of lilacs in the spring. I purchased my sample of ink from Vanness Pens.
Viola is a light, spring purple.
There is a strong blue undertone, which pools up in large swabs.
Let's take a look at how the ink behaves on fountain pen friendly papers: Rhodia, Tomoe River, and Leuchtturm.
Dry time: 15 seconds
Water resistance: Low
Show through: Medium
On 20 pound copy paper the ink performed well, no issues that I noticed.
I used a medium Pelikan M400 White Tortoise on Tomoe River paper. The ink had an average flow.
Overall, it's a interesting color. It's not one that I've seen before in other brands, which is great. I love that it has some interesting shading.
Disclaimer: I purchased this ink myself, and all photos and opinions are my own. There are no affiliate links on this page.